The present invention relates to a gas turbine, and particularly to a high moisture gas turbine cycle using high moisture air for combustion.
High moisture gas turbine cycles have been disclosed, for example, in Japanese Patent Laid-open Nos. Sho 57-79224, Sho 57-79225, and Sho 58-101228, and U.S. Pat. No. 4,448,018, in which thermal energy of gas turbine combustion exhaust gas or the like is recovered to produce water vapor; the water vapor is mixed in combustion air for the gas turbine; and a turbine is driven by high moisture combustion exhaust gas obtained by a combustor, whereby the output power and the power generating efficiency are enhanced.
A configuration of one of the above high moisture gas turbine cycles has been disclosed, in which a low pressure compressor and a high pressure compressor are arranged in series, and a direct or indirect heat exchanger is interposed between both the compressors, wherein heat recover is performed by injecting water to compressed air emerged from the high pressure compressor.
In each known example, however, it is required to inject a large amount of water to compressed air to be supplied to a combustor for obtaining a desired output power or a desired power generating efficiency.
When air containing large amount of water is supplied to the combustor, the combustion stability of the combustor becomes low. In particular, for a power generating gas turbine, premixed combustion of air and fuel in a narrow stable combustion range, which is performed for reducing the amount of Nox of exhaust gas, is largely affected by the supply of air including a large amount of water.
Accordingly, the present invention provides a high moisture gas turbine installation capable of enhancing combustion stability while ensuring desired output power and power generating efficiency.
The present invention also provides a high moisture gas turbine installation capable of enhancing combustion stability while ensuring desired output power and power generating efficiency by reducing the amount of water required to obtain the desired output power and power generating efficiency.
The present invention also provides a high moisture gas turbine capable of miniaturizing a humidifier, an apparatus for recovering water from gas turbine exhaust gas, and the like by reducing the amount of supplied water, and further increasing the output power and power generating efficiency by reducing loss in compressed air and exhaust gas.
In a high moisture gas turbine cycle, a large amount of moisture is added to air for combustion. In this case, if moisture is partially added to air supplied from atmospheric air, a humidifier can be miniaturized and a heat exchanger for supplying hot water to the humidifier can be also miniaturized as compared with the method in which moisture is added to compressed air.
As a result, a pressure loss in equipment connected between a gas turbine and air compressors such as the humidifier and heat exchanger is reduced, and thereby the power generating efficiency of the gas turbine can be improved. Also, the power of the air compressor can be reduced even if the air compressor is not divided or a plurality of the air compressors are not arranged in series, and thereby the output power and the power generating efficiency of the gas turbine can be improved.
To be more specific, the present invention provides a gas turbine installation including a compressor for compressing air supplied thereto and discharging the compressed air, a combustor for burning fuel together with the air discharged from the compressor, and a turbine driven by combustion gas generated by the combustor, the gas turbine installation comprising:
a spraying apparatus, which is provided in an air suction chamber disposed on the upstream side of the compressor, and which is used for spraying water droplets to air to be supplied to the compressor thereby making the temperature of the air to be supplied to the compressor lower than the temperature of atmospheric air, the sprayed water droplets being introduced in the compressor together with the air whose temperature has been lowered and being evaporated in a period in which the water droplets flow down in the compressor together with the air;
a water adding apparatus for adding water to the compressed air discharged from the compressor, the compressed air containing moisture added in the form of water droplets by the spraying apparatus;
a regenerator for receiving the compressed air containing moisture added by the water adding apparatus and heating the compressed air by using a gas turbine exhaust gas as a heat source; and
a path through which the compressed air heated by the regenerator is supplied to the combustor.
For a gas turbine system in which the spraying apparatus 11 is simply provided to the compressor, since the compression work is reduced, the effect of increasing the output power becomes large; however, since the temperature of the air at the outlet of the compressor is lowered, that is, the temperature of the air to e supplied to the compressor is lowered, the used amount of fuel at the combustor becomes large, so that it is not expect to increase the power generating efficiency.
The present invention also provides a gas turbine installation including a compressor for compressing air supplied thereto and discharging the compressed air, a combustor for burning fuel together with the air discharged from the compressor, and a turbine driven by combustion gas generated by the combustor, the gas turbine installation comprising:
a spraying apparatus, which is provided in an air suction chamber disposed on the upstream side of the compressor, and which is used for spraying water droplets to air to be supplied to the compressor, evaporating part of the sprayed water droplets until the water droplets are led in the compressor, and evaporating the non-evaporated water droplets led in the compressor together with the air in a period in which the water droplets flow down in the compressor together with the air;
a water adding apparatus for adding water to the compressed air discharged from the compressor, the compressed air containing moisture added in the form of water droplets by the spraying apparatus;
a regenerator for receiving the compressed air containing moisture added by the water adding apparatus and heating the compressed air by using a gas turbine exhaust gas as a heat source; and
a path through which the compressed air heated by the regenerator is supplied to the combustor.
The present invention also provides a gas turbine installation including a compressor for compressing air supplied thereto and discharging the compressed air, a combustor for burning fuel together with the air discharged from the compressor, and a turbine driven by combustion gas generated by the combustor, the gas turbine installation comprising:
a spraying apparatus, which is provided in an air suction chamber disposed on the upstream side of the compressor, and which is used for spraying water droplets to air to be supplied to the compressor, evaporating part of the sprayed water droplets until the water droplets are led in the compressor, and evaporating the non-evaporated water droplets led in the compressor together with the air in a period in which the water droplets flow down in the compressor together with the air;
a water adding apparatus for adding water to the compressed air discharged from the compressor, the compressed air containing moisture added in the form of water droplets by the spraying apparatus;
a regenerator for receiving the compressed air containing moisture added by the water adding apparatus and heating the compressed air by using a gas turbine exhaust gas as a heat source;
a path through which the compressed air heated by the regenerator is supplied to the combustor; and
a path used for recovering moisture from combustion exhaust gas having passed through the regenerator and supplying the recovered moisture to at least one of the spraying apparatus and the water adding apparatus.
With these configurations, the amount of supplied water can be reduced. Also since the recovered water containing heat of exhaust gas can be reused and the heat generated by itself can be returned to the upstream side from the combustor, the power generating efficiency of the gas turbine can be further improved. Further, the recovered water is heated by using compressed air or gas turbine exhaust gas as a heat source, a heating apparatus for heating water before addition of the water to the compressed air can be miniaturized. This makes it possible to reduce the pressure loss and hence to further enhance the power generating efficiency.
In the above-described gas turbine installation, preferably, the spraying apparatus comprises sprayers which are arranged in a plurality of steps along the flow of the air in the suction air chamber in such a manner that the temperature of water sprayed from one, positioned on the downstream side, of the sprayers is higher than the temperature of water sprayed from one, positioned on the upstream side, of the sprayers.
With this configuration, since the flow rate in weight at the inlet of the compressor is increased and thereby the water droplets being easy to be evaporated in the compressor can be supplied from the inlet of the compressor, it is possible to stably increase the evaporation amount in the compressor.
To be more specific, suction air is cooled by the water sprayers at the front steps to increase the flow rate in weight of the air, and high temperature water is sprayed to the air from the water sprayers at the rear steps disposed near the inlet of the compressor, whereby water being easy to be evaporated in the compressor can be largely contained in the air to be supplied to the compressor.
In this regard, by making large the ratio of the amount of water supplied to the air by the spraying apparatus to the amount of water added to the compressed air by the water adding apparatus, it is possible to further enhance the output power and the power generating efficiency.
The above-described gas turbine installation preferably further includes:
a control unit for controlling the amount of water added to air in such a manner that the amount of water sprayed to the air by the spraying apparatus is in a range of 1/50 to 1/5 of the amount of water added to the compressed air by the water adding apparatus.
The above amount of water sprayed to the air by the spraying apparatus is preferably in a range of 1/25 to 1/10 of the amount of water added to the compressed air by the water adding apparatus.
The above-described gas turbine installation preferably further includes:
a control unit for controlling the amount of water added to air in such a manner that the amount of water sprayed to the air by the spraying apparatus is in a range of 1/50 to 1/5 of the amount of water added to the compressed air by the water adding apparatus;
wherein the ratio of the amount of circulated water to and from the water adding apparatus to the amount of water added to the compressed air by the water adding apparatus is controlled to be in a range of 70% to 95%.
Further, the above ratio is preferably in a range of 1/25 to 1/10.
In the above-described gas turbine installation, preferably, the ratio of the amount of water sprayed to the air by the spraying apparatus to the flow rate in weight of the air is controlled to be in a range of 0.2% to 5.0%, and the ratio of the amount of water added to the compressed air by the water adding apparatus to the flow rate in weight of the compressed air discharged from the compressor is controlled to be in a range of 30% or less.
The above ratio of the amount of water sprayed to the air by the spraying apparatus to the flow rate in weight of the air is more preferably in a range of 0.4% to 2.5%
The present invention also provides a gas turbine installation including a compressor for compressing air supplied thereto and discharging the compressed air, a combustor for burning fuel together with the air discharged from the compressor, and a turbine driven by combustion gas generated by the combustor, the gas turbine installation comprising:
a spraying apparatus, which is provided in an air suction chamber disposed on the upstream side of the compressor, and which is used for spraying water droplets to air to be supplied to the compressor, evaporating part of the sprayed water droplets until the water droplets are led in the compressor, and evaporating the non-evaporated water droplets led in the compressor together with the air in a period in which the water droplets flow down in the compressor together with the air;
a water adding apparatus for adding water to the compressed air discharged from the compressor, the compressed air containing moisture added in the form of water droplets by the spraying apparatus;
a regenerator for receiving the compressed air containing moisture added by the water adding apparatus and heating the compressed air by using a gas turbine exhaust gas as a heat source;
a path through which the compressed air heated by the regenerator is supplied to the combustor; and
a control unit for controlling the temperature of water in such a manner that the temperature of water supplied to the water adding apparatus is higher than the temperature of water supplied to the spraying apparatus.
The control unit can be configured as a water supplying apparatus capable of supplying water at a plurality of temperature levels or an apparatus for recovering water from exhaust gas.
The present invention also provides a gas turbine installation including a compressor for compressing air supplied thereto and discharging the compressed air, a combustor for burning fuel together with the air discharged from the compressor, and a turbine driven by combustion gas generated by the combustor, the gas turbine installation comprising:
a spraying apparatus, which is provided in an air suction chamber disposed on the upstream side of the compressor, and which is used for spraying water droplets to air to be supplied to the compressor, evaporating part of the sprayed water droplets until the water droplets are led in the compressor, and evaporating the non-evaporated water droplets led in the compressor together with the air in a period in which the water droplets flow down in the compressor together with the air;
a water adding apparatus for adding water to the compressed air discharged from the compressor, the compressed air containing moisture added in the form of water droplets by the spraying apparatus;
a regenerator for receiving the compressed air containing moisture added by the water adding apparatus and heating the compressed air by using a gas turbine exhaust gas as a heat source;
a path through which the compressed air heated by the regenerator is supplied to the combustor;
a water supply path used for recovering moisture from combustion exhaust gas having passed through the regenerator and supplying the recovered moisture to the spraying apparatus and the water adding apparatus; and
a cooling apparatus for cooling the compressed air flowing on the upstream side of the water adding apparatus by heat exchange with the water supplied to the water adding apparatus.
The above-described gas turbine installation, preferably, further includes, in place of the water supply path, added water supply path used for recovering moisture from combustion exhaust gas having passed through the regenerator and supplying the recovered moisture to the water adding apparatus; and a spray water supply path through which spray water is led from an external source outside the system in the spraying apparatus.
The present invention also provides a gas turbine installation including a compressor for compressing air supplied thereto and discharging the compressed air, a combustor for burning fuel together with the air discharged from the compressor, and a turbine driven by combustion gas generated by the combustor, the gas turbine installation comprising:
a spraying apparatus, which is provided in an air suction chamber disposed on the upstream side of the compressor, and which is used for spraying water droplets to air to be supplied to the compressor, evaporating part of the sprayed water droplets until the water droplets are led in the compressor, and evaporating the non-evaporated water droplets led in the compressor together with the air in a period in which the water droplets flow down in the compressor together with the air;
a water adding apparatus for adding water to the compressed air discharged from the compressor, the compressed air containing moisture added in the form of water droplets by the spraying apparatus;
a regenerator for receiving the compressed air containing moisture added by the water adding apparatus and heating the compressed air by using a gas turbine exhaust gas as a heat source;
the combustor to which the compressed air heated by the regenerator is supplied;
a water supply path used for recovering moisture from combustion exhaust gas having passed through the regenerator and supplying the recovered moisture to the spraying apparatus and the water adding apparatus; and
a supplied water heater for heating water to be supplied to the water adding apparatus by using combustion exhaust gas having passed through the regenerator as a heat source.
The above-described gas turbine preferably further includes:
a control unit for reducing, upon decrease in load, the amount of water to be added to the compressed air by the water adding apparatus and then reducing the amount of water to be sprayed to the air by the spraying apparatus; or a control unit for increasing, upon increase in load, the amount of water to be sprayed to the air by the spraying apparatus and then increasing the amount of water to be added to the compressed air by the water adding apparatus.
The present invention also provides an efficiency increasing apparatus, provided in a gas turbine installation, for recovering thermal energy of gas turbine exhaust gas thereby improving power generating efficiency, the gas turbine installation including a compressor for compressing air supplied thereto and discharging the compressed air, a combustor for burning fuel together with the air discharged from the compressor, and a turbine driven by combustion gas generated by the combustor;
the efficiency increasing apparatus comprising:
a spraying apparatus, which is provided in an air suction chamber disposed on the upstream side of the compressor, and which is used for spraying water droplets to air to be supplied to the compressor, evaporating part of the sprayed water droplets until the water droplets are led in the compressor, and evaporating the non-evaporated water droplets led in the compressor together with the air in a period in which the water droplets flow down in the compressor together with the air;
a water adding apparatus for adding water to the compressed air discharged from the compressor, the compressed air containing moisture added in the form of water droplets by the spraying apparatus; and
a regenerator for receiving the compressed air containing moisture added by the water adding apparatus and heating the compressed air by using a gas turbine exhaust gas as a heat source.
The present invention also provides an efficiency increasing apparatus, provided in a gas turbine installation, for recovering thermal energy of gas turbine exhaust gas thereby improving power generating efficiency, the gas turbine installation including a compressor for compressing air supplied thereto and discharging the compressed air, a combustor for burning fuel together with the air discharged from the compressor, and a turbine driven by combustion gas generated by the combustor;
the efficiency increasing apparatus comprising:
a spraying apparatus, which is provided in an air suction chamber disposed on the upstream side of the compressor, and which is used for spraying water droplets to air to be supplied to the compressor, evaporating part of the sprayed water droplets until the water droplets are led in the compressor, and evaporating the non-evaporated water droplets led in the compressor together with the air in a period in which the water droplets flow down in the compressor together with the air;
a water adding apparatus for adding water to the compressed air discharged from the compressor, the compressed air containing moisture added in the form of water droplets by the spraying apparatus;
a regenerator for receiving the compressed air containing moisture added by the water adding apparatus and heating the compressed air by using a gas turbine exhaust gas as a heat source; and
a path used for recovering moisture from combustion exhaust gas having passed through the regenerator and supplying the recovered moisture to at least the water adding apparatus of a group of the spraying apparatus and the water adding apparatus.
The above-described efficiency increasing apparatus preferably further includes:
a control unit for controlling the amount of water added to air in such a manner that the amount of water sprayed to the air by the spraying apparatus is in a range of 1/50 to 1/5 of the amount of water sprayed to the compressed air by the water adding apparatus. The amount of water sprayed to the air by the spraying apparatus is more preferably in a range of 1/25 to 1/10 of the amount of water sprayed to the compressed air by the water adding apparatus.